1. Field of the Invention
The invention relates to a turbine wheel for a gas operated medical, in particular dental-medical, handpiece and such a handpiece having a turbine wheel, and a method for milling blades of the turbine wheel.
2. Description of Related Technology
A turbine wheel and a handpiece of these kinds are described in DE 198 33 249 A1. In the case of this previously known turbine wheel or handpiece, the blades of the turbine wheel have at their front side, which can be acted upon with compressed air, in each case a concave circular arc section forming a curvature surface, the axis of curvature of which develops approximately radially, the handpiece having a delivery line for compressed air, the outlet of which is directed secantially at a side edge region of the blades. As a consequence, in operation of the turbine wheel or of the handpiece, the compressed air flow is in each case deflected at the curved front side, whereby it leaves the front side in the axially opposite edge region. Through this, the airflow not only gives up its impact energy to the respective blade, but also an additional energy, brought about by means of the deflection, which increases the power of the turbine drive.
In the case of a turbine wheel or handpiece of the kinds concerned here there is fundamentally required a high power exploitation and in particular power increase. This is because the turbine wheel or the handpiece should have, in particular in its forward region, a structural size which is as small as possible, so that upon treatment or working of the human or animal body, or an artificial part thereof, the view of the treatment site is affected as little as possible. This applies in particular for treatment sites in body cavities, in which the available space is restricted, such as is the case in the mouth of a patient or model head, with regard to a dental-medical handpiece. The greater is the delivered power of the turbine drive, the smaller can this, or the turbine wheel, or the region of the handpiece concerned, be formed, and a thus greater field of view of the operation site stands available to the operator.
The object of the invention is thus, with a turbine wheel or a handpiece of the kinds indicated in the introduction, to increase the drive power or to better exploit the drive power.